Leinster, who visit Firhill on Friday, and Ulster, who are at Murrayfield on Sunday, are confident they will be able to travel by ferry.
The visit of European champions and table-topping Leinster, including Ireland captain Brian O'Driscoll, is Glasgow's biggest game of the season as they continue their push for the Magners League play-offs.
Stena Line are partners of both Irish provinces and will transport the squads to Scotland if flights remain suspended because of the cloud of volcanic ash drifting south from Iceland.
With some flights having been allowed out of airports in Ireland and Scotland last week at a time when many others were suspended, the travelling rugby teams remain hopeful they can come by their normal methods. If they do have to resort to surface travel, the extra journey time would be no more than a minor inconvenience.
Like the Magners League, the main matches of the week in European football are still expected to go ahead as planned, but other sports have not been so fortunate.
A substantial section of the Formula 1 industry, for example, is still stranded in and around Shanghai following the weekend's Chinese Grand Prix.
Formula 1 supremo Bernie Ecclestone has insisted there is no threat to the Barcelona Grand Prix on 9 May, but the difficulty involved in getting people and machinery from Asia to Europe could have an impact on preparations fore that race.
Several drivers have taken the opportunity to go on holiday, but teams face an anxious wait while they work out how to get to Spain in plenty of time for the Barcelona race.
"I was always going to go away for a few days, relaxing after this," Chinese Grand Prix winner Jenson Button said. "I'm hopefully going to be heading back to Europe at the end of the week, so we will see about that."
Button's McLaren team-mate Lewis Hamilton has flown to South Africa for a sponsorship commitment. Red Bull's Mark Webber has returned to his native Australia.
Of the 12 teams, the Lotus Racing employees are arguably the most fortunate courtesy of owner and AirAsia entrepreneur Tony Fernandes, as it is understood he has flown them on to the team's financial home in Kuala Lumpur until flights into Europe again become available. McLaren hope to charter a plane to Spain tomorrow and then negotiate a route home from there.
"We have said if it is a big enough plane then anyone else can come on board," said team principal Martin Whitmarsh.
"I think some teams were hesitating but they are now jumping on board pretty quick.
"Hopefully, as Spain is about the only place you can fly into, we can get them there on Wednesday and onto coaches for Santander or road route home."
Next Sunday's London Marathon may see a decline in international entrants because of the travel disruption. Organisers are looking at other methods of transport for international elite entrants.
The Moroccan Golf Classic has been postponed but the Ballantine's Championship in Korea on the full PGA European Tour is unlikely to be affected, with the majority of players already in Asia after the Volvo China Open.
Team Sky's Bradley Wiggins was among the cyclists to miss the weekend's Amstel Gold race in the Netherlands while team-mate Kurt-Asle Arvesen was trapped on a North Sea oil rig for several days until late on Sunday night.
Great Britain's ice hockey team made a 26-hour bus journey to Slovenia where they are competing in Group B of Division One of the World Championships – and won their first two matches. Defenseman Stephen Lee has also embarked on a 24-hour drive from his home in Hull.
British three-day eventing star Oliver Townend has embarked on a marathon journey to Kentucky to keep his Rolex Grand Slam dream alive. Townend left his Shropshire base yesterday and is using Eurostar and a taxi to get to Madrid before flying.
Belle Vue speedway team have three riders stuck in Scandinavia ahead of their clash against Ipswich. They are allowed to use any riders available in the country.
In rugby league, the Challenge Cup match between Widnes and Lezignan was postponed at the weekend. The final leg of the Diving World Series, scheduled for next weekend, has been moved from Sheffield to Mexico.